Study And Implement Of The DataBase Grid Query System Based On OGSA

Now data of scientific computing and commercial application fields is increasing at an amazing speed. The need of accessing and managing these complicated and grat data in a uniform way becomes more and more impending. With the development of grid technology, how to access the existed databases, provide a uniform interface to access the databases, and compose the existed databases to make a virtual database is a issue that worth to study.In this paper, We study on XML technology and grid technology, analyse the advantage of integration of the isomerous databases by the grid thechnology and work over the plan and implenemt of the database grid query system to access isomerous databases. On the base of research and analysis of the architecture and inner implementary process of OGSA-DAI, we advance two modules that are defined by user own. The two modules are metadata service mldule and distributed query processing service module. By the intercommunion of the two modules, we implement to query the isomerous databases distributedly.MDS module defines the meta data and is to manage the meta data. It defines meta data on the characteristics of the grid, constitutes service buffer to improve the efficiency in finding services, and analysises on how to extract the database service metadata from service data providede by GDSF. With the intercommunion of MDS module, DQP module implement to query on isomerous databases. By design three submodules of query analysis, decompose of query task, and performation of the subtask, we implement the user's query. It analyses on how to express and optimize the query from users, how to decompose the query task, and how to implement the module of query performation. At last, based on the model, this paper set up the prototype system and test it. The result of the test shows that the design of the prototype is feasible, and reaches the require of the design.